The invention relates to conveyor apparatus for the transportation of plates, strips or sheets of material on continuous belts. It has particular application to the transportation, at high speed of corrugated cardboard after it has been cut into pieces.
From a machine producing sheets of corrugated cardboard cut continuously to a required size, the sheets are conveyed at high speed, after cutting, to a stacking device. To enable this operation to be carried out efficiently, it is necessary for the sheets to be positioned accurately in relation to each other on the conveying device, and for them to follow exactly the motion of translation communicated to them by the conveyor in time and space.
There are several types of conveyor apparatus at present in existence, which are suited to this operation. In one such apparatus, the sheets are applied onto the bands or belts of a conveyor by means of pressure-rollers placed transversely at regular intervals across the entire width of the conveyor. Another type of conveyor system collects the sheets sandwiched between two sets of superimposed synchronous belts or bands. Pressure-rollers for example, are transversely placed so as to increase the pressure on the sheets exerted by the two sets of bands or belts. Apparatus using perforated suction belts are also known which involve much expenditure of energy and wear.
The above apparatus do not exert on the sheets a regular and continuous pressure in space on their entire surface. With the sheets not being held in position sufficiently against the belts of the conveyor, pile-ups may arise if one of the sheets moves out of place in relation to the others. Given the rhythmic movement of the machine, pile-ups generally have troublesome consequences and can cause prolonged stoppages in manufacture.